diatoms and water changes q's

[rpick]

i have started up my reef tank with tap water and chemicals to netralize the metals. have 40+ lbs of live rock (20 uncured) for the past 3 weeks.
no spike in water qualities since, but switched over to ro water last thursday although i now have diatoms on substrate and rocks. been topping tank off with ro water (unsalted).
just got 2 5 gal water jugs and went to the store today to get ro water and bough 'reef crystals'.
after adding the salt, i did a 10% water change.
water quality:
am .5
ph 8.3
ni .25
na 20
salinity 1.026
have'nt tested calcium yet
questions:
should i top off tank with salt water or unslated?
do i need to do a bigger water change?
do i need to add the raw shrimp to get the water to spike with am and ni levels?
with the above information and diatoms, is the tank already cycled and ready for cleanup crew or do i need the raw shrimp to jump start the cycling?

 

[benj2112]

Well, first you had 20+ lbs. of uncured rock...that would be enough to get things going in your tank IMO.
You have .5 ammonia from your test so you want to wait for that to go to zero...then wait for nitrite to go to zero.
Top your tank off with freshwater. The h2o evaporates, but the salt stays so you don't want to add more saltwater. That would raise your salinity.
Wait on the clean-up crew till ammonia and nitrite are zero. Also, don't do any water changes till after you get your 0 readings on ammonia and nitrite as well. That will only make the cycle take longer.

 

[mudplayerx]

A diatom bloom in a new tank is a sign that the cycle is going as it should.

 

[benj2112]

Aren't diatoms using silicates in the water more than anything else? Not really part of the ammonia/nitrite/nitrate cycle.

 

[tuna dan]

Yea they feed off the materials in tap water once they exhust the food supply they will die off but adding tap water may continue to feed them

 

[rpick]

I've stopped using tap water since 03/24. hopefully, this will stop it. is the tank ready for the shrimp?